Suppose that 9 weeks ago stock KMS was at $11 per share, and 2 weeks ago it was at $39 per share.

A) On average, how much does the stock increase per week? $ per week.  

B) What is the price of the stock this week? $  

C) Write an equation to model this situation (use w\displaystyle {w} for weeks and d\displaystyle {d} for dollars).